The invention relates to an electrical switch. More particularly, the invention provides an electrical switch having a height that is at least half reduced in comparison with that the prior art.
FIG. 1 is a sectional view illustrating a micro switch of the prior art, usually used in command output of mouse, keyboard, or power supply switch of electrical devices. As illustrated, the traditional micro switch principally comprises an assembly of a base 2b and an upper cover 1b. First and second insertion legs 3b, 4b are arranged through the base 2b. First and second positioning portions 31b, 32b are formed on the first insertion leg 3b. A hole 11b is defined through the upper cover 1b. A conductor resilient plate 5b is further mounted over the first and second insertion legs 3b, 4b. The plate 5b includes a first portion having a mounting part 51b mounted to the first positioning portion 31b, and a second portion provided with a contact pad 52b that is placed vis-à-vis the second insertion leg 4b. A resilient tongue 53b, integrally formed with the plate 5b, further extends and bends toward the base 2b, the tongue 53b having an end portion fastened to the second positioning portion 32b. A push button 6b is mounted over the plate 5b and is exposed through the hole 11b. When the user presses the push button 6b, the push button 6b consequently presses the plate 5b. With the mounting part 51b of the plate 5b electrically connected to the first insertion leg 3b, a pressing on the push button 6b thus causes an electrical contact of the contact pad 52b with the second insertion leg 4b by deflection of the plate 5b. An electrical switch having small contact deflection is hence traditionally constructed.
As illustrated in the drawings, mounting spaces have to be necessary left to allow pushing of the push button 6b and bending of the resilient tongue 53b. As a result, the height of the traditional switch (without the insertion legs 3b, 4b) is usually 7.3 mm. As electrical equipment become increasingly smaller, a traditional approach to accommodate the above electrical switch is to reduce the thickness of the upper cover 1b and the thickness of the base 2b. However, this approach negatively results in weakening the electrical switch, and causes cracks in the upper cover 1b or base 2b during product transportation or when the user pushes on the electrical switch. As the thickness of the base 2b or/and upper cover 1b is reduced, the switch further is more subject to deformation during injection molding or assembly in its fabrication process. As a result, the yield is negatively reduced.
Moreover, the above switch suffers another disadvantage. Because the resilient tongue 53b is positioned on the second positioning portion 32b by fitting, if only the plate 5b presents a defective deviation due to various fabrication deviations, the tongue 53b easily separates from the second positioning portion 32b after a certain time of utilization. Moreover, because the tongue 53b is proximate to the second insertion leg 4b, the tongue 53b when separated thus easily contacts with the second insertion leg 4b, thereby establishing an undesirable electrical contact.
It is therefore an object of the invention to provide an electrical switch that can overcome the above deficiencies and has a height that is dimensionally reduced a half.
To accomplish the above and other objectives, the electrical switch of the invention comprises a conductor resilient plate having a resilient tongue that extends and bends toward the upper cover and is placed parallel with the push button on a same side of the conductor resilient plate. Thereby, traditional mounting spaces are not required. Furthermore, even if the resilient tongue inadvertently separates from the second positioning portion, the resilient tongue would upwardly deviate and therefore would not causes an electrical contact with the second insertion leg. A secure control of the command output is thereby achieved.
In accordance with another aspect of the invention, the base of the electrical switch further includes a reinforcement integrally formed with the base by injection molding. By means of the reinforcement, the thickness of the base and/or the upper cover can be reduced without adversely weakening the electrical switch.
To provide a further understanding of the invention, the following detailed description illustrates embodiments and examples of the invention, this detailed description being provided only for illustration of the invention.